Biological Classification 2 Flashcards
what is the artificial system of classification
n this type of classification plants are classified on the basis of one or two
morphological characters/Few morphological characters i.e. over all morphological
characters are not considered.
Equal weightage is given to both vegetative and reproductive characters in artificial
classification.
Linnaeus wrote this classification in his book - “Genera Plantarum”.
He classified all plants mainly on the basis of stamens (male sex organ). Group of
stamens is called androecium.
Linnaeus classfied all plants into 24 classes.
what is the natural system of classification
In this type, plants are classified on the basis of their complete or gross
morphology. In this system the characters of whole plant are included (root, shoot
etc.) Maximum characters are taken as basis in this classification.
Natural classification is based on natural affinities among the organisms and
consider not only the external features but also internal features like ultra structure,
anatomy, embryology and phytochemistry.
what is numerical taxonomy or phenetic taxonomy
In this system plants are classified on the basis of numbers of similarities and
dissimilarities. This classification is easily carried out by using computers and it is based on
all observable characteristics. In this classification number and codes are assigned to all
the characters and the data are prepared and then processed. Those organisms which
have maximum similarities are placed in same group. In this way each character is given
equal importance and at the same time hundreds of characters can be considered.
give theophrastus system of classification ( 2nd one)
He is known as Father of ancient plant taxonomy and Father of botany.
(ii) Theophrastus proposed the classification of plant kingdom. He classified plant
kingdom into four groups on the basis of growth habit -
(a) Trees
(b) Shrubs
(c) Under shrubs
(d) Herbs
explain george and bentham classification
They wrote the book “Genera plantarum”.
(iv)
In this book, Bentham and Hooker gave the biggest and natural classification of
spermatophyta (seeded plants)
they divided into:
(i) gymnosperm
(ii) dicotyledonae
(iii) monocotyledonae
The classification of Bentham and Hooker was mainly based on the floral characters.
The classification of Bentham and Hooker was natural.
It is the simplest classification because this classification is based on actual
observations.
they did not follow evolutionary relationships because in it, gymnosperms
are placed in between dicots and monocots. The sequence of evolution is as follows :-
Phylogeny = Gymnosperm Dicots Monocots.
what is carl woese classification based on
sequence of r-rna
what is the most resistant bacteria
Maximum resistant bacteria is cocci